package com.example.reflection;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Scanner;

/**
 * 打印一个类的全部信息
 */
public class ReflectionTest {
    public static void main(String[] args) throws ReflectiveOperationException{
        String name;
        if(args.length > 0){
            name = args[0];
        }else{
            var in = new Scanner(System.in);
            System.out.println("请输入类名，比如 java.util.Date ");
            name = in.next();
        }

        Class cl = Class.forName(name);
        Class supercl = cl.getSuperclass();
        String modifiers = Modifier.toString(cl.getModifiers());
        if(modifiers.length() > 0){
            System.out.print(modifiers + " ");
        }
        System.out.print("class " + name);
        if(supercl != null && supercl != Object.class){
            System.out.print(" extends " + supercl.getName());
        }
        System.out.print("\n{\n");
        printConstructors(cl);
        System.out.println();
        printMethods(cl);
        System.out.println();
        printFields(cl);
        System.out.println("}");
    }
    public static void printConstructors(Class cl){
        Constructor[] constructors = cl.getDeclaredConstructors();

        for(Constructor c : constructors){
            String name = c.getName();
            System.out.print("    ");
            String modifiers = Modifier.toString(c.getModifiers());
            if(modifiers.length() > 0){
                System.out.print(modifiers + " ");
            }
            System.out.print(name + "(");

            //打印参数类型
            Class[] paramTypes = c.getParameterTypes();
            for(int j = 0; j < paramTypes.length; j++){
                if(j > 0){
                    System.out.print(", ");
                }
                System.out.print(paramTypes[j].getName());
            }
            System.out.println(");");
        }
    }
    public static void printMethods(Class cl){
        Method[] methods = cl.getDeclaredMethods();

        for(Method m : methods){
            Class retType = m.getReturnType();
            String name = m.getName();

            System.out.print("    ");
            String modifiers = Modifier.toString(m.getModifiers());
            if(modifiers.length() > 0){
                System.out.print(modifiers + " ");
            }
            System.out.print(retType.getName() + " " + name + "(");

            Class[] paramTypes = m.getParameterTypes();
            for(int j = 0; j < paramTypes.length; j++){
                if(j > 0){
                    System.out.print(", ");
                }
                System.out.print(paramTypes[j] + " ");
            }
            System.out.println(");");
        }
    }
    public static void printFields(Class cl){
        Field[] fields = cl.getFields();

        for(Field f : fields){
            Class type = f.getType();
            String name = type.getName();
            System.out.print("    ");
            String modifiers = Modifier.toString(f.getModifiers());
            if(modifiers.length() > 0){
                System.out.print(modifiers + " ");
            }
            System.out.println(type.getName() + " " + name + ";");
        }
    }
}
